Furnace.



N. W, ROBINSON. FURNACE.

APPLICAUON .HLED JAN, 10,1918. 138mm 2 SHEETS-SHEET I.

Patented Oct; 8, 1918.

N. W. ROBINSON.

FURNACE.

APPLICATION FILED JAN. 10. I918.

1,281,251 Patented 00. 8,1918.

2 SHEETS-4m 2.

$572655" w" Wig?? f0? FURNACE.

Application filed January 10, 1918.

To all whom it may concern:

Be it known that I, NORMAN W. ROBIN- soN, a citizen of the United States, residing at Chicago, county of Cook, State of Illinois have invented a certain new and useful Improvement in Furnaces, and declare the following to be a full, clear, and exact description of the same, such as Wlll enable others skilled in the art to. which it pertains to make and use the same, reference bein hadto the accompanying drawings, whic form a part of this specification.

My invention has for its object to produce a simple and novel furnace construction which will insure more perfect combustion than in ordinary furnaces.

A further object of my invention is to produce a simple and novel attachment for an ordinary furnace whereby its efiiclency will be greatly increased.

A further object of my invention is to produce a simple substitute for the commonly used brick arch which shall possess all of the advantages of the latter,together with the additional advantage of supplying preheated air in a manner to insure perfect combustion, without placing an obstructlon in front of the flues in the common forms of boilers and preventing them from being cleaned through the fire box.

Thevarious features of novelty whereby my invention is characterized will hereinafter be pointed out with particularity in the claims; but, for a full understandlng of (myinvention and of its objects and ad vantages, reference may be had to the following detailed description taken in connection with the accompanying drawmgs,

. wherein:

Figure l is a view, partly in elevation and partly in section of a boiler hav1ng 1ts furnace equipped in accordance with my 1nvention;

- Figs. 7 and 8 are sectlons through the plate or wall of the air preheater, showing modifications in construction which may be employed also in the baflie plate.

Specification of Letters Patent.

Serial No..211,120.

Patented Oct. 8, 1918 i Referring to the drawings, 1 represents a boiler having a fire box, 2, and smoke flues, 3, leading from the fire box. These parts may be of any usual or suitable construction and design.

In the. fire box, at some distance in front of the rear end thereof and at adistance above the grate, 4:, preferably greater than the depth of the bed of coals to be maintained at this point is a transverse air box or tunnel, 5, which may conveniently be made square in cross section, as shown, but

may take any other shape. The rear wall of the member 5 is extended upwardly as indicated at 6 so the air box or tunnel as a whole forms a transverse partition which projects upwardly above the plane of the lower row or rows of flues. This arrangement would prevent a cleaner from being introduced into the lower fiues throughthe fire box and therefore, in order to avoid this objection, Iv support the air tunnel or box so thatit may be revolved about its longitudinal axis. In this way the air tunnel or box may be shifted so as to carry its upwardly-projecting part, 6, from its normal position indicated in full lines in Fig. 1 to that indicated in dotted lines when access to the lower flues is desired.

Air is admitted into the interior of the air tunnel or box in any suitable manner and, after being heated, passes out into the fire chamber through slots, 7 and 8, formed in the top and rear walls of the air tunnel or box; the slots, 7, in the top wall preferably extending to the front edge so that some .of the air will be delivered into the .fire chamber in the forward direction.

Above and just in front of the member 5 is arranged a baffle plate or curtain, 9, which extends across the fire box and down from thetop thereof to a level preferably somewhat below the -top of the part 6 of the member 5. The bafile plate or curtain is hung in such a manner that it may be swung up out of the way when access to the upper flues is desired. The bafile plate may have a few holes, 10, extending through it.

' It will be seen that the members 5 and 9, form what might be termed a sectional arch, the sections of which are spaced apart in 'such a way that smoke may pass between them in anindirect path toward the fiues, mixingrwithpreheated air during such passage. Preheated air is also delivered through the slots in the back of the sec 7 tional arch to mingle with the gaseousprod- 1 nets and flame in the rear end of the tire box. Thus much more nearly perfect combustion is obtained than is possible with a simple arch.

NVhile the structural details of-my invention may be widely varied, the particular design shown in the drawings maybe used-t advantage.

o In the arrangement shown, the bearings for the air. heater 5 are nipples, 11 and 12,

extending'through both the inner and outer sheets, l3and 14, forming the side walls of the fire box. At one end'of the air heater is a spring pressed plunger, 15, which, when the air heater is placed in position, maybe pushed completely into the end of the air heater so as to permit the latter to be brought into registration with the nipples, whereupon the plunger will be pressed outwardly by its spring so as to project'into the nipple 11. The plunger may conveniently be slidable in a tubular extension, 16, projecting into the air heater from ajcap or head, 17, closing one end of the latter.

The member 16 has one or more slots, 18, extending longitudinally thereof and the plunger "has alaterally projecting ear or cars, 19, fitting into the slot or slots to prevent the plunger from turning. i

,To the opposite end of the air heater is connected a long open-ended tubular member, 20, which passesthroughthe nipple, 12,

and the outer wall, 21, of the furnace. On the extreme outer end of the member 20 is fixeda handle, 22, by which the member 20 and the airheater may be turned as heretofore explained. A wall v plate or flange, 23, maybe secured to the outer face of the wall, 21, around the tubular member 20; the wall plate or flange being provided withdiametrically opposed holes, 24, either of which is adapted to register with a similar hole in the handle 22. A pin, 25, maybe inserted through the hole in the handle and either one of the holes in the wall plate orflange forthe purpose of locking the air heating tunnel or box in either of its two positions. The member 20 ismade as large in diameter as possible so as to permit the air to be drawn freely into the air-heater and the interior of the "air heater'is preferably unobstructed and preferably of approximately uniform cross sectional area, so that there will .be no choking or retarding of the flow of air through thejheater. In the outer end of the member 20 there may be placed a damper of any suitable type, the same being preferably so constructed that the air inlet can never be-completely closed; This may conveniently be accomplished by'placing in 'the end of the member'20 a plate, 26, which has across sectional area which is only a small fraction of the cross sectional area of the inlet opening and providing a movable of the cross sectional'area of the tube 20. ith this arrangement, the size of the air inlet may be varied but the inlet can not accidentally be closed and air .w ill atall the bafiie plate is swung inwardly toward the flues'until it is. parallel with the top: of

the firebox, the hook-like. portion may be slipped on and off the supporting trunnions while in other positions of the'baflle plate it aneior plate, 27 whose area, together with V that'of the men1ber 2 6,,is not more than half is prevented from being disengaged: from the trunnions. The'baflle plate is prevented from being accidentally swung into-a position which .will release it by means of stops constructed in the same manneras thetrunnions but engaging with the rear side of the baffle plate'near the lower end of-the'latter.

The baffle plate may be provided in'the lower edge with'a notch, 32, together with an opening, 33, located just above the notch. This permits a poker or bar having a'hooked end to be hooked under-the lower edge ofthe baffle plate, the notch serving to guide'the hooked end into the opening'33 as the'bafiie plate is swung upwardly.

The members 5 and-9 may berconstructed in any suitable way. 'In' the arrangement shown in'LFigs. 1 1 and 3, the" member '5' is shown as made of'lcast iron-covered by a the member 5, including the extension 6, together with the member 9, may be made as shownin Fig-7, comprising afcomp'arativ'ely thin'wall, 41, of cast iron coated onlboth sides with .a layer of asbestos cement,"42;; or

layer, 40, of asbestos cement; Thew'alls'fof they may be made asshOWnin'FigYS, .of a

concrete center, 43, covered on'both faces with ironite, r

, While I have illustrated and described with particularity only a single preferred form of'my invention, IIjdo' not desire to be limited to the exact structural detailsthus illustrated and.described ;but intend to cover all forms and arrangements which .come within the terms employed in the definitions of my invention. constituting the {appended claims. 3

I claim: 1. The combination with afire box-having a grate and'horizonta li flues leading theretending across the fire box'in front 'of and in from, of a perforated airbox or,tunnel'.ex-' 1 the vicinity of the level of the lowermost flues, said air box or tunnel having a wall or flange extending upwardly past the lowermost flues, trunnions at the longitudinal axis of the air box or tunnel supporting the latter so as to permit it to be rotated to carry said wall or flange downwardly below the lowermost flues, one of said trunnions being in the form of an open-ended tube connecting the interior of the air box or tunnel with the outside atmosphere.

2. The combination with a fire box having a grate and horizontal flues leading therefrom, of a perforated air box or tunnel extending across the fire box in front of and in the vicinity of the level of the lowermost flues, said air box or tunnel having a wall or flange extending upwardly past the lowermost flues, trunnions at the longitudinal axis of the air box or tunnel for supporting the same so as to permit it to be rotated to carry said wall or flange downwardly below the lowermost flues, and means for admitting air into the interior of said box or tunnel.

3. The combination with a fire box having a grate and horizontal flues leading therefrom, of a perforated air box or tunnel extending across the fire box in front of and in the vicinity of the level of the lowermost flues, said air box or tunnel having a wall or flange extending upwardly past the lowermost flues, trunnions at the longitudinal axis of the air box or tunnel supporting the latter so as to permit it to be rotated to carry said wall or flange downwardly below the lowermost flues, one of said trunnions being in the form of an open-ended tube connecting the interior of the air box or tunnel with the outside atmosphere, and a handle on the outer end of said tubular trunnion for turning the same and said air box or tunnel.

4. The combination with a fire box having a grate and horizontal flues leading therefrom, of a perforated air box or tunnel extending across the fire box in front of and in the vicinity of the level of the lowermost fiues, said air box or tunnel having a wall or flange extending upwardly past the lowermost flues, trunnions at the longitudinal axis of the air box or tunnel supporting the latter so as to perimt it to be rotated to carry said wall or flange downwardly below the lowermost flues, one of said trunnions being in the form of an open-ended tube connecting the interior of the air box or tunnel with the outside atmosphere, a damper for controlling the admission of air into the tubular trunnion, and ahandle 011 one of said trunnions for turning the same and said air box or tunnel.

5. The combination with a fire box, of a perforated air box or tunnel approximately square in cross section extending across the interior thereof, trunnions at the ends of the air box or tunnel at about the longitudinal axis of the latter adapted to support the air box or tunnel for angular movements about its longitudinal axis, one of the walls of the air box or tunnel being extended laterally beyond the adjacent side, means for admitting air into the interior of the air box or tunnel, and a baffle plate hung at its upper end in the upper portion of the fire box and extending downwardly below the level of the upper edge of said extended wall when the latter lies in its highest position.

6. The combination with a fire box, of an air box or tunnel approximately square in cross section extending across the interior thereof and perforated so as to permit air to pass therefrom into the fire box, trunnions at the ends of the box or tunnel at about the longitudinal axis of the latter adapted to support the box or tunnel so as to permit it to move angularly about its said axis, one of the walls of the box or tunnel being extended laterally beyond the adjacent side, means for admitting air into the interior of the box or tunnel, and a baifle plate arranged across the upper portion of the fire box and extending downwardly below the level of the upper edge of said extended wall when the latter lies in its highest position.

In testimony whereof I sign this specification.

NORMAN W. ROBINSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

